Drive mechanism for imparting reciprocating motion



Jan. 28, 1964 F. s. AMBROSE DRIVE MECHANISM FOR IMPARTING RECIPROCA TING MOTION Original Filed July 9. 1957 3 Sheets-Sheet 1 INVENTOR. FREDERICK S. AMBROSE HIS ATTORNEY Jan. 28, 1964 F. s. AMBROSE 3,119,275

DRIVE MECHANISM FOR IMPARTING RECIPROCATING MOTION Original Filed July 9. 1957 3 Sheets-Sheet 2 INVENTOR.

Fneoemcx s. AMBROSE ATTORNEY Jan. 28, 1964 F. s. AMBROSE 3,119,275

DRIVE MECHANISM FOR IMPARTING RECIPROCATING MOTION Original Filed July 9. 1957 4 s Sheets-Sheet 3 INVENTOR. FREDERICK 5. AMBROSE L4, ATTORNEY United States Patent Oil ice 3,119,275 Patented Jan. 28, 1964 3,119,275 DRIVE MECHANISM FOR HMPARTING nncrrnoearnso MOTION Frederick S. Ambrose, Tucson, Ariz., assignor, by mesne 9 Claims. (Cl. 74-61) This invention relates to an improved reciprocatory drive mechanism particularly adapted for use with concentrating tables.

This application is a division of my copending application Serial Number 670,798, filed July 9, 1957, now Patent No. 3,075,644, which, in turn, is a continuation-inpart of my copending application Serial Number 613,165, filed October 1, 1956, now abandoned.

The concentrating table type of materials separating apparatus is used extensively to separate mixed materials having difierent specific gravities. The basic elements of the concentrating table assembly are the riffied deck and the head or drive mechanism. The head mechanism imparts a substantially horizontal reciprocating motion to the deck. It is this head, or drive mechanism, which forms the subject of the present invention. Prior Patent No. 3,075,644 may be referred to for details of the concentrating table, and the manner of connecting the drive mechanism to the table.

It has been found that a peculiar vibratory motion of the concentrating table deck is required to obtain proper separation of the mixture. The forward motion of the deck must be terminated suddenly and the direction of motion quickly reversed. The reverse motion must be terminated slowly and the direction of motion slowly reversed. In other words, for proper separation there must be an accelerated forward motion terminating in a quick reversal rather than a smooth harmonic motion. The accelerated forward motion assists in both stratifying the material in the conveying liquid and in providing forward inertia to the particle. The quick reversal literally pulls the deck out from under the particle so that the particle as it attempts to settle in the liquid has advanced longitudinally along the deck. This peculiar vibratory motion may be defined as a rectilinear differential motion. In fact, the conveying ability of the motion is dependent upon the differential of the motion.

The primary object of my invention is to provide a drive means that is capable of producing its own driving forces and its own stopping forces.

This and other objects will become apparent from time to time throughout the specification and claims as hereinafter related.

This invention comprises the new and improved construction and combination of parts and their operating relation to each other which will be described more fully hereinafter and the novelty of which will be particularly pointed out and distinctly claimed.

In the accompanying drawings to be taken as part of this specification there is fully and clearly illustrated a practical embodiment of my invention in which drawmgs:

FIGURE 1 is a detail sectional view through the improved drive mechanism housing, illustrating in side elevation the arrangement of the gearing and eccentric members comprising the drive mechanism.

FIGURE 2 is a sectional plan view of the drive mechanism taken along the line 2-2 of FIGURE 1 and illustrating in plan the arrangement of the gearing and eccentric members within the drive mechanism.

FIGURE 3 is a sectional view in front elevation of the drive mechanism taken along the line 33 of FIGURE 1.

The drive mechanism 10, forming the subject of this application, has an external housing 60 with side Walls 62 and 64 having outwardly extending flanges thereon. Adjacent the front and rear edges of the housing 60 along the flanges of side walls 62 and 64 there are positioned cable connectors 66. The cable connectors 66 are similar in construction and are operable to hingedly secure suspending cables (not shown) to the drive mechanism 10. Secured to the front end of the drive mechanism housing 60 there is a coupling member 68 which has a pair of outwardly extending flanges 70 and 72. The flanges 70 and 72 are spaced from each other in parallel relation and have aligned apertures 74 therethrough. A pin member hingedly secures the drive mechanism 10 to a materials separating table. With the coupling member 68 the concentrating table may be secured to the drive mechanism 10 so that the direction of motion imparted by the drive mechanism 10 will be transmitted through the connecting pin member to the table, thus assuring the transmittal of the rectilinear motion of the drive mechanism 10.

The detail construction of the operating parts of the drive or head mechanism 10 is shown in FIGURES 1, 2 and 3. Two pairs of parallel shafts 182, 184 and 186, 188 are positioned within the drive mechanism housing 60 and are supported by the housing side walls 62 and 64. The shafts 182, 184 and 186, 188 are each rotatably secured in pairs of self-aligning bearings operatively secured in the side walls 62 and 64. The shaft 188 extends beyond the housing side wall 62 and has a sheave 22 secured thereon (FIGURE 2). A pair of gears 194 and 196, which have the same pitch diameter and have the same number of gear teeth, are centrally secured to shafts 182 and 184 and are in meshing relation with each other. The shafts 186 and 188 have a pair of gears 198 and 200, which have the same pitch diameter and have the same number of teeth, secured centrally thereon. The pitch diameter of gears 194 and 196 is twice that of gears 198 and 200 and gears 194 and 196 have twice the number of gear teeth than gears 198 and 200. Gear 198 is in meshing relation with the gear 194 so that upon rotation of gear 194 gear 198 will rotate in the opposite direction with twice the speed of gear 194. Similarly gear 200 is in meshing relation with the gear 196 so that upon rotation of gear 200 gear 196 will rotate in the opposite direction at one-half the speed of gear 200. Therefore, when sheave 22 rotates, gears 198 and 200 rotate in opposite directions to each other at the same speed and the gears 194 and 196 rotate in a direction opposite to each other at one-half the speed of gears 198 and 200.

Secured symmetrically on opposite sides of the gear 194 on shaft 182 are a pair of large counterweights or eccentric members 202 and 204 (FIGURE 2). The eccentric members are laterally equidistant from the gear 194 and revolve with the shaft 182. Secured to the shaft 184 are a second pair of large eccentric members 206 and 208. The large eccentric members 206 and 208 are spaced equidistantly from the gear 196 in a manner so they do not interfere with the eccentric members 202 and 204 as both gears 194 and 196 rotate in opposite directions. The radial displacement of the centers of gravity from the axis of rotation and the weight of the eccentric members 202, 204, 206 and 208 are equal and are arranged on the shafts 182 and 184 so that the effective forces of these eccentric members are cancelled in a vertical plane and are combined in a horizontal plane.

In a similar manner a pair of small eccentric members 210 and 212 are symmetrically secured to the shaft 186 adjacent to the gear 198 and revolve with shaft 136. A second pair of small eccentric members 214 and 216 are secured to the shaft 188, equidistant from the gear 200 :component.

and adjacent the housing side walls 62 and 64. The eccentric members 214 and 216 are so positioned that they do not interfere with the other small eccentric members upon rotation of the gears 198 and 200 in opposite directions. The radial displacement of the centers of gravity from the axis of rotation of the eccentric members 210, 212, 214, 216 are equal and are arranged on the shafts 186 and 188 so that the effective forces of these eccentric members are cancelled in a vertical plane and .are combined in a horizontal plane.

All of the large eccentric members 202, 204, 206 and 208 have a pair of apertures 218 and 220 therethrough which are adapted to receive weights or plugs 222 and 224 therein. Similarly the small eccentric members 210, 212, 214 and 216 have apertures 226 and 228 therethrough which are also adapted to receive weights or plugs 230 and 232 therein. Any suitable means may be provided to retain the various weights in their respective apertures. By changing the weights or plugs in the various eccentric members the length of stroke and the differential of the drive mechanism may be changed. Since particle travel on concentrator decks is dependent upon the motion differential, the particle travel may also be increased or decreased by changing the weights in the various eccentrics.

FIGURE 1 illustrates one arrangement of the respective positions of the eccentric members to each other. In this figure the large eccentric members 202, 204, 206 .and 208 are exerting a force in a direction toward the front coupling member 68 which, in effect, is a force toward the decks 2 and 4. The small eccentric members 210, 212, 214 and 216 are exerting a force in a direction opposite to the large eccentric members which, in effect, is away from the decks 2 and 4.

As the respective eccentric members rotate the resultant force of each of the eccentrics continually changes in direction. This resultant force has a horizontal component and a vertical component. Due to the geared connection between the pairs of large eccentric members the vertical component of the respective pairs of large eccentric members are always equal and opposite to each other so that the sum of the vertical components for the large eccentric members is always substantially zero. Accordingly, centrifugal forces of the large eccentrics may beexpressed by the remaining horizontal component. Similarly the centrifugal forces exerted by the small eccentric members may be expressed by their horizontal For example, in FIGURE 1, assume the .large eccentric members 202, 204, 206 and 208 have rotated to a position where eccentrics 202 and 204 are 45 below the horizontal plane. At this point weights 202 and 204 have a downward vertical component and a rearward horizontal component. Eccentrics 206 and 208 at the same instant because of their geared relation to eccentrics 202 and 204 rotate in the opposite direction the same number of degrees and have an upward vertical component and a rearward horizontal component. The downward vertical component of eccentrics 202 and 204 is substantially equal to the upward vertical component of eccentrics 206 and 208 and hence the vertical component of the large eccentrics 202, 204, 206 and 208 cancel out. Since the horizontal component of these .eccentrics are in the same direction their forces are additive which results in a horizontal rearward force of a given amplitude. In this manner as the large eccentrics rotate their centrifugal forces may be expressed by their horizontal component.

The small eccentric members 210, 212, 214 and 216 are also arranged so that the vertical component of eccentrics 210 and 212 are substantially equal to and opposite to the vertical components of eccentrics 214 and 216. Therefore any motion produced by the drive mechanism will be in a substantially horizontal plane and will be substantially rectilinear. The substantially horizontal rectilinear force results from the absence of vertical components between the large eccentrics and also an absence of vertical components between the small eccentrics.

The differential portion of the motion imparted by the drive mechanism 10 may be changed by increasing or decreasing the additive horizontal components of the various eccentrics in one direction and either increasing or decreasing the additive horizontal components in the other direction. This can be accomplished by either increasing or decreasing the effective weights of the various eccentrics by changing or removing the various weights or plugs 222, 224, 226 and 228. The horizontal com ponents may also be changed by changing the phase relationship between the large eccentric members and the small eccentric members. By changing the phase relation I mean rotating the small eccentrics about their axes a given number of degrees while the large eccentrics remain in a horizontal position. This may be accomplished by disengaging gear 198 from gear 194 and gear 200 from gear 196. While the large eccentrics re' main in the position illustrated in FIGURE 1 the small eccentrics are moved toward each other until small eccentrics 214 and 216 are a given number of degrees above horizontal and the small eccentrics 210 and 212 are substantially the same number of degrees below horizontal. By changing the phase relationship between the large eccentrics and the small eccentrics the resultant horizontal components of all eccentrics is proportionately changed.

In the previous discussion it has been assumed that the effective weights of the large eccentrics are substantially equal to each other and the effective weights of the small eccentrics are substantially equal to each other.

In operating the drive, rotary motion which is imparted to the input drive pulley 22 is translated to horizontal rectilinear differential motion of the drive mechanism by means of the eccentric members rotating therein. A satisfactory speed for the shafts 182 and 184 has been found to be approximately 270 rpm. As heretofore stated, for each revolution of the shafts 182 and 184 one complete stroke is exerted by the drive mechanism 10. Thus, under these conditions, the drive mechanism 10 imparts approximately 270 strokes per minute to the materials separating decks to which it may be connected. This will provide a vibratory motion which is suddenly reversed in one direction, but slowly reversed in the opposite direction to impart a conveying action to the member to which the drive is connected.

My .drive mechanism makes it possible to suspend a plurality of materials separating decks from a common supporting structure and eliminates the need for any means for absorbing the vibratory forces exerted by the decks. The drive mechanism provides a horizontal rectilinear differential motion which is useful in the separation of materials having different specific gravities, and not .only produces the movement required for the particular motion but also produces its own stopping forces.

Although the drive mechanism 10 has been described in conjunction with a materials separating apparatus it should be understood that it is within the scope of this invention to utilize the motion obtained by the drive mechanism 10 in conjunction with other types of material treating apparatus.

According -to the provisions of the patent statutes, I have explained the principle, preferred constructions and mode of operation of my invention and have illustrated and described what I now consider to represent its best embodiments. However, I desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

I claim:

1. In a drive mechanism the combination comprising four shafts rotatably supported in parallel spaced relation to each other, means to rotate said shafts in timed relation to each other, four pairs of eccentric weights non-rotatably secured one pair to each of said shafts, two of said pairs of weights being larger than the remaining two pairs of weights, said pairs of weights being arranged axially on said shafts so that the individual Weights of one larger pair of weights and one smaller pair of weights rotate in two common parallel planes and the individual weights of the other larger pair of weights and the other smaller pair of weights rotate in two other common parallel planes, all of said parallel planes being normal to the longitudinal axes of said shafts, said shafts and said larger weights being so arranged that the rotational paths of said larger weights overlap and the rota tional paths of a pair of said larger weights overlaps the rotational path of a pair of said smaller weights, said eccentric weights being arranged on said shafts to impart substantially rectilinear differential motion to said drive mechanism upon rotation of said shafts.

2. In a drive mechanism the combination comprising first, second, third, and fourth shafts rotatably supported in parallel spaced relation to each other, constantly meshing gearing secured to said shafts and arranged to rotate said shafts in timed relation to each other, a first pair of eccentric weights non-rotatably secured to said first shaft to rotate one in each of first and second parallel planes, said first and second parallel planes being normal to the longitudinal axes of said shafts, a second pair of eccentric weights non-rotatably secured to said second shaft to rotate one in each of third and fourth parallel planes, said third and fourth parallel planes being parallel to said first and second planes and spaced therefrom, a third pair of eccentric weights non-rotatably secured to said third shaft to rotate one in each of said first and second parallel planes, a fourth pair of eccentric weights non-rotatably secured to said fourth shaft to rotate one in each of said third and fourth parallel planes, the diameters of rotation of second and third pairs of weights being greater than the distance between said first and second shafts, between said second and third shafts, between said third and fourth shafts, and between said first and fourth shafts, said pairs of eccentric weights secured to each of said shafts being arranged to impart substantially rectilinear differential motion to said drive mechanism upon rotation of said shafts, said motion being in a plane parallel to said first, second, third and fourth planes.

3. In a drive mechanism the combination comprising first, second, third and fourth shafts rotatably supported in parallel spaced relation to each other, a gear train including first, second, third, and fourth gears nonrotatably secured respectively to said first, second, third and fourth shafts, said gear train disposed in a common gear plane, said gear plane being normal to the longitudinal axes of said shafts, power input means nonrotatably secured to one of said shafts for introducing rotary power into said drive mechanism, a first pair of eccentric weights non-rotatably secured to said first shaft to rotate one in each of first and second parallel planes, said first and second parallel planes being parallel to said gear plane and being located at equal distances on each side of said gear plane, said first gear meshing with said second gear, a second pair of eccentric weights non-rotatably secured to said second shaft to rotate one in each of third and fourth parallel planes, said third and fourth parallel planes being parallel to said gear plane and located at equal distances on each side of said gear plane, said second gear meshing with said third gear, a third pair of eccentric weights non-rotatably secured to said third shaft to rotate one in each of said first and second parallel planes, said third gear meshing with said fourth gear, a fourth pair of eccentric weights non-rotatably secured to said fourth shaft to rotate one in each of said third and fourth parallel planes, the diameters of rotation of said first, second, third and fourth pairs of weights being greater than the pitch diameters of said first, second, third and fourth gears respectively, said pairs of eccentric weights secured to each of said shafts being arranged to impart substantially rectilinear differential motion to said drive mechanism upon rotation of said shafts, said motion being in a plane parallel to said gear plane.

4. The combination of claim 3 wherein said second and third shafts are arranged to rotate in opposite directions at the same velocity and said first and fourth shafts are arranged to rotate in opposite directions at twice the velocity of said second and third shafts.

5. The combination of claim 3 wherein the weights of said first and fourth pairs of weights are identical and the weights of said second and third pairs of weights are identical.

6. In a drive mechanism the combination comprising first, second, third and fourth shafts rotatably supported in spaced relation to each other, with the first and fourth shafts having longitudinal axes lying in a common plane and the second and third shafts having longitudinal axes lying in a common plane to position the first shaft adjacent the second and fourth shafts, the second shaft adjacent the first and third shafts, the third shaft adjacent the second and fourth shafts and the fourth shaft adjacent the first and third shafts, with the first and third shafts and the second and fourth shafts forming diagonally opposed shaft pairs, a gear train including first, second, third and fourth gears non-rotatably secured respectively to said first, second, third and fourth shafts, said gear train disposed in a common gear plane, power input means non-rotatably secured to one of said shafts for introducing rotary power into said drive mechanism, a first pair of eccentric weights non-rotatably secured to said first shaft to rotate one in each of first and second parallel planes, said first and second planes being parallel to said common gear plane and being located at equal distances on each side of said gear plane, said first gear meshing with said second gear, a second pair of eccentric weights non-rotatably secured to said second shaft to rotate one in each of third and fourth parallel planes, said third and fourth parallel planes being parallel to said gear plane and located at equal distances on each side of said gear plane, said second gear meshing with said third gear, a third pair of eccentric weights nonrotatably secured to said third shaft to rotate one in each of said first and second parallel planes, said third gear meshing With said fourth gear, a fourth pair of eccentric Weights non-rotatably secured to said fourth shaft to rotate one in each of said third and fourth planes, whereby said eccentric weights of adjacent shafts rotate in separate parallel planes and the eccentric weights of diagonally opposed shafts rotate in common planes, the diameters of rotation of said first, second, third and fourth pairs of weights being greater than the pitch diameters of said first, second, third and fourth gears respectively, said pairs of eccentric Weights non-rotatably secured to each of said shafts being arranged to impart substantially rectilinear differential motion to said drive mechanism upon rotation of said shafts, said motion being in a plane parallel to said gear plane.

7. Vibrating means for screens and the like for producing an alternating force along a desired line of action comprising parallel shafts, each of said shafts having a longitudinal axis, each shaft further having an eccentric weight portion disposed eccentrically of its axis, said vibrating means having a central axis, said shafts being arranged with their axes parallel to said central axis of said vibrating means, said shafts further being arranged in two pairs diametrically disposed with respect to said central axis, means drivingly interconnecting said shafts for timed relative rotation of the shafts of each pair in the same direction and the shafts of each pair in a direction opposite that of the shafts of the other pair.

8. The vibrating means of claim 7 wherein each shaft References Cited in the file of this patent UNITED STATES PATENTS Miller Oct. 1, Parks Jan. 30, Ott Apr. 30, Hittson July 13, Maust Sept. 16, Oswalt Nov. 30, Booth Oct. 16,

Disclaimer 3,119,275.Frede1 2'07c S. Ambrose, Tucson, Ariz. DRIVE MECHANISM FOR IMPARTING RE'GIPROOATING MOTION. Patent dated Jan. 28, 1964. Disclaimer filed Nov. 13, 1964, by the assignee, Gail's Manufacturing Oompcm Hereby enters this disclaimer to claims 7, '8 and 9 of said patent.

[Oficial Gazette March 2, 1.965.] 

1. IN A DRIVE MECHANISM THE COMBINATION COMPRISING FOUR SHAFTS ROTATABLY SUPPORTED IN PARALLEL SPACED RELATION TO EACH OTHER, MEANS TO ROTATE SAID SHAFTS IN TIMED RELATION TO EACH OTHER, FOUR PAIRS OF ECCENTRIC WEIGHTS NON-ROTATABLY SECURED ONE PAIR TO EACH OF SAID SAHFTS, TWO OF SAID PAIRS OF WEIGHTS BEING LARGER THAN THE REMAINING TWO PAIRS OF WEIGHTS, SAID PAIRS OF WEIGHTS BEING ARRANGED AXIALLY ON SAID SHAFTS SO THAT THE INDIVIDUAL WEIGHTS OF ONE LARGER PAIR OF WEIGHTS AND ONE SMALLER PAIR OF WEIGHTS ROTATE IN TWO COMMON PARALLEL PLANES AND THE INDIVIDUAL WEIGHTS OF THE OTHER LARGER PAIR OF WEIGHTS AND THE OTHER SMALLER PAIR OF WEIGHTS ROTATE IN TWO OTHER COMMON PARALLEL PLANES, ALL OF SAID PARALLEL PLANES BEING NORMAL TO THE LONGITUDINAL AXES OF SAID SHAFTS, SAID SHAFTS AND SAID LARGER WEIGHTS BEING SO ARRANGED THAT THE ROTATIONAL PATHS OF SAID LARGER WEIGHTS OVERLAP AND THE ROTATIONAL PATHS OF A PAIR OF SAID LARGER WEIGHTS OVERLAPS THE ROTATIONAL PATH OF A PAIR OF SAID SMALLER WEIGHTS, SAID ECCENTRIC WEIGHTS BEING ARRANGED ON SAID SHAFTS TO IMPART SUBSTANTIALLY RECTILINEAR DIFFERENTIAL MOTION TO SAID DRIVE MECHANISM UPON ROTATION OF SAID SHAFTS. 